ES2454740T3 - System for washing a gas turbine aeromotor - Google Patents

Abstract

A washing system for washing a gas turbine engine (1) of an aircraft (40) comprising: a spraying device (90); a washing unit (31,35) adapted to distribute washing liquid to said spraying device (90); and a positioning device (34) adapted to place said spraying device (90) thereby allowing a positioning of said communication device (90) in a washing operation position relative to an inlet (110) of said motor ( 1) gas turbine, characterized in that the spraying device (90) includes: a central body (91); several manifolds (92) annularly each with different diameters, arranged symmetrically around the central body (91); and multiple nozzles (93) arranged symmetrically around the central body (91), the nozzles (93) being arranged around the manifolds (92) and adapted to inject said washing liquid into said inlet (110) of the engine during an operation of washing, wherein said spraying device (90) comprises a unit with essentially rotational symmetry with a symmetry axis (501) being the center of symmetry; and wherein, when the spraying device (90) is in said washing operation position, the central axis (501) of the spraying device (90) is essentially aligned with the motor shaft of the turbine engine (1) Of gas.

Description

System for washing a gas turbine aeromotor

Technical Field

The present invention relates generally to the field of gas turbine engine washing, and more specifically to systems and to a vehicle for washing a gas turbine engine installed in an aircraft or aircraft.

Background of the invention

A gas turbine aircraft engine comprises a compressor that compresses ambient air, a combustion chamber that burns fuel along with compressed air and a turbine to drive the compressor. The combustion gases when expanding actuate the turbine and also result in a thrust for propulsion.

Airplanes that fly at high altitude breathe in the clean air that predominates at this point. However, at airfields the air contains foreign particles in the form of aerosols that enter the engine with the air current. Typical particles found in the air of the airfield are pollen, insects, hydrocarbons that come from industrial activities and salt that comes from the nearby sea. While the plane is on the ground at the airport there are additional particles to consider such as combustion residues in the engine exhaust gases from the airplane being rolled, chemicals that come from the defrosting of the aircraft and earth material such as dust. Most foreign particles will follow the path of the gas through the engine and will exit with the exhaust gases. However, there are particles with tack properties on components in the engine gas path, especially in the engine compressor section. This is known as accumulation of unwanted material.

The accumulation of unwanted material in the compressor results in a change in the properties of the boundary layer air stream of the compressor components. The presence of foreign particles results in an increase in the surface roughness of the component. When air flows over the surface the increase in surface roughness results in a thickening of the air flow of the boundary layer. The thickening of the air flow of the boundary layer has negative effects on the aerodynamics of the compressor in the form of a reduced mass flow. At the rear edge of the blade the air stream forms a wake. The wake forms a vortex type of turbulence with a negative impact on the air flow. The thicker the boundary layer, the stronger the turbulence in the wake and the more the mass flow is reduced. In addition, a thick boundary layer and a stronger rear edge turbulence result in a reduced compression gain which in turn results in the compressor with accumulation of unwanted material compressing air at a reduced pressure ratio. Any person skilled in the art of hot engine work cycles understands that a reduced pressure ratio results in a lower thermal efficiency of the motor. The compressor with accumulation of unwanted material not only reduces mass flow and pressure gain but also reduces the iso-entropic efficiency of the compressor. Reduced compressor efficiency means that the compressor requires more energy to compress the same amount of air. The energy to drive the compressor is taken from the turbine through the shaft. With the turbine requiring more energy to drive the compressor there will be less energy to create thrust for the propulsion. For the pilot of the plane this means that he must regulate to obtain more fuel so that the reduced thrust is compensated. Regulation to obtain more fuel means that fuel consumption increases and therefore increases operating costs.

Loss of performance caused by the accumulation of unwanted material in the compressor also reduces engine durability. As more fuel has to be burned to reach a required thrust level, an increase in the combustion temperature of the engine is derived. When the pilot on its way accelerates to take off, the components of the hot section of the engine are under a critical high temperature load. Controlling the flue gas temperature is a key factor in monitoring engine performance. The control temperature known as the exhaust gas temperature (EGT) is measured with sensors in the path downstream of the combustion chamber outlet. The EGT is carefully monitored by recording both the temperature and the exposure time. During the life of the engine the registration of the EGT is checked frequently. At a certain point the engine will be required to be taken out of service for a review in which the components of the hot section are inspected and replaced if required.

The accumulation of unwanted material in the compressor also has a negative effect on the environment. The difference in fuel consumption of a virgin engine delivered from the factory and an engine with a compressor with accumulation of unwanted material can typically be 1%. With the increase in fuel consumption, an increase in greenhouse gas emissions such as carbon dioxide is derived. Typically the combustion of 1 kg of aviation fuel results in the formation of 3.1 kg of carbon dioxide. In addition, the high temperature of the combustion chamber has a negative effect on the

environment. With the increase in the combustion temperature, an increase in NOx formation is derived. The formation of NOx depends to a large extent on the design of the burner and a general number cannot be foreseen. However, any incremental temperature rise to a given burner design results in an increase in NOx formation. Therefore, the accumulation of unwanted material in the compressor has negative effects on the performance of an air motor such as increased fuel consumption, reduced engine life and increasing emissions.

Several engine wash techniques have been developed over the years so that the negative effects of the accumulation of unwanted material are reduced or eliminated. The simplest washing method is to take a garden hose and spray water at the motor inlet. However, this method has limited success due to the simple nature of the process. An alternative method is to scrub the blades by hand with a brush and liquid. This method has limited success since it does not allow cleaning of the blades inside the compressor. In addition, it takes time, Asplund U.S. Patent No. 5,868,860 describes the use of a manifold to wash air motors. In addition, the patent describes the use of high liquid pressure as a means to provide a high liquid velocity, which together with the approval of the motor shaft will improve cleaning efficiency.

EP 0628477 A1 describes an aircraft service system comprising four robotic arms mounted on the ground. The arms can be moved so that an ideal nozzle arrangement at the end of each arm can defrost or wash the plane. Defrosting fluid is sprayed along the fuselage, the wings and optionally, the engine. The system is controlled autonomously once an operator has typed in the type of aircraft to be cleaned or defrosted.

US Patent No. 6,394,108 describes a thin flexible hose, one end of which is inserted from the compressor inlet to the compressor outlet between the compressor blades. At the inserted end of the hose there is a nozzle. The hose is slowly removed out of the compressor while the liquid is being pumped to the nose and sprayed through the nozzle. However, washing efficiency is limited because the compressor rotor is not able to rotate during washing. Despite existing technologies and patents for washing, there is a need for new technologies that allow a practical wash to be conducted in a less intense, low-cost, simple and safe way of working.

US Patent No. 5,011,540 describes a rectangular support frame arranged to be applied on a bell mouth part of a gas turbine engine. A single manifold ring is provided on one side of a support wall part of the support frame and twelve nozzles extend from the manifold, through the support wall part, to the mouth of the gas turbine engine. Liquid solvent is sprayed into the gas turbine engine from the nozzles.

Summary of the invention

Commercial air traffic has been developed as an efficient tool for transporting passengers and items or goods from one place to another. The air fleet today comprises a large number of types of aircraft supplied by many aircraft manufacturers. The engines used to propel these aircraft are manufactured by several engine manufacturers, which supply engines of different sizes and with different performance characteristics. Engine manufacturers also supply engines that are compatible with third-party engines, which means that alternative, but not identical, engines are available for the same aircraft. This results in a large possible combination of aircraft engines in aircraft types. This has been found to be a disadvantage when washing is carried out since the washing equipment needs to be sized and designed to meet individual designs. It is the purpose of this invention to simplify the washing of the engines.

The implementation of the engine wash described with reference to fig. 1 is also considered common knowledge in this field. A cross-sectional view of a two-shaft turbo fan motor is shown in fig. 1. The arrows show the flow of gas through the engine. The motor 1 is constructed around a rotor shaft 14 which at its front end is connected to the fan 15 and at the rear end to the turbine 16. The turbine 16 drives the fan 15. A second shaft 19 is shaped like a coaxial shaft to the first shaft 14. The shaft 19 is connected at its front end to the compressor 17 and at the rear end to the turbine 18. The turbine 18 drives the compressor 17. The motor 1 has an inlet 110 where the inlet air enters the engine. The fairing 11 serves as a guide for the intake air stream. The inlet air flow is driven by the fan 15. A part of the inlet air exits through the outlet 11. The remaining part of the inlet air enters the central motor at the inlet 13. The air to the motor core is a then compressed by the compressor 17. The compressed air together with the fuel (not shown) is burned in the combustion chamber 101 resulting in pressurized hot combustion gases. Pressurized hot combustion gases expand towards the outlet 12 of the engine core. Gas expansion

Hot combustion is done in two stages. In a first stage the combustion gases expand at an intermediate pressure while driving the turbine 18. In a second stage the hot combustion gases expand towards the ambient pressure while driving the turbine 16. The combustion gases leave the engine through the Exit 12 at high speed providing thrust. The gas coming from the outlet 12 together with the air coming from the outlet 11 together constitute the engine thrust.

A washing device according to the prior art consists of a manifold 102 in the form of a tube that at one end is connected to a nozzle 103 and at the other end connected to a coupling 104. The hose 105 is at one end connected to the coupling 104 while the other end is connected to a liquid pump (not shown). The manifold 102 is resting on the inlet fairing 11 and is held in a firm position during washing by securing it with a belt or similar means. The washing procedure begins by rotating the motor shaft with the help of the starter motor. The pump pumps a nozzle wash liquid 103 where it atomizes and forms a spray 104. The rotation of the shaft results in a flow of air through the engine. This air flow drives the liquid through the engine and releases unwanted accumulation material. The unwanted accumulation material is released by a mechanical and chemical action of the washing liquid. The cleaning effect is improved by the rotation of the tree since the dampening of the blades creates a film of liquid that will be subjected to forces such as air aspiration and centrifugal forces during washing.

The prior art describes the use of a manifold with nozzles to inject the wash fluid into the engine inlet. It is common for the manifold to be placed in the entry fairing while using the fairing for its support. The manifold is thus temporarily installed for the washing process and is removed after the completion of the wash. Fig. 2 shows an example of a prior art manifold when installed at the inlet of a turbo fan motor. Similar parts are shown with the same reference numbers as in fig. 1. The manifold 102 is resting on the inlet fairing 11 of the air intake to the engine 1. The manifold 102 is manufactured to adapt to the shape of the inlet fairing so that it is in a firm position during washing. To ensure that the manifold is held in a firm position, a belt 21 is attached to the manifold outside the inlet and pressed against a hook (not shown) hooked to the motor outlet. The washing liquid is pumped by a pump (not shown) through the hose 105 through the coupling 104 to the manifold 102 and also to the nozzles 103. The manifold 102 is in the form of a tube that serves as a conduit for the liquid washing The manifold 102 also acts as a rigid support for the nozzles so as to keep the nozzles in a firm position during washing. For a good washing result, an appropriate positioning of the manifold is mandatory. For this purpose the manifold must be designed and conceived with respect to the shape of the entry fairing and the characteristic geometry of the motor. In addition, the manifold must be designed and conceived so that it properly supports the nozzles against the reaction forces of the spray during washing.

As mentioned above there are many different types of aircraft and many different aircraft engines which results in many different inlet air fairing designs. As the manifold is supported on the entry fairing this means that many different manifolds will have to be manufactured so that they serve a large fleet of aircraft.

The manifolds according to the prior art are large as a result of the large intake geometry of large aircraft engines. The multiples therefore require significant storage space in storage.

The invention as described in the preferred embodiments describes a universal manifold that is significantly smaller in size compared to the prior art manifolds. It is the purpose of this invention to reduce the storage space by providing a small manifold.

The multiples according to the prior art design result in a significant amount of work hours to conceive, manufacture and test for adjustment. In addition, the manifold is put into production only in small series since there may not be too many aircraft with a specific combination of the engine and entry fairing. This invention as described in the preferred embodiments describes a universal manifold applicable to a wide range of aircraft and aircraft engines. The manifold according to the invention is designed primarily once but can be put into production in large series. This will reduce the costs for the universal manifold. It is the purpose of this invention to reduce costs for the air operator.

The washing of aircraft engines can be conducted by an airline operator or by a specialist organization such as an Airport Engine Wash Service Center. If the washing is conducted by a service center, the disadvantage of having many multiples in this is even more an important factor since the service center will serve a large number of different aircraft and different aircraft engines. It is the purpose of this invention to reduce costs for the operator of the Washing Service Center of

Airport engines.

Thus, the invention provides a washing system for washing a gas turbine engine of an aircraft as defined in the appended claims.

Other objects and advantages of the present invention will be described below by means of an exemplary embodiment.

Brief description of the drawings

A preferred embodiment of the invention will be described in greater detail below with reference to the accompanying drawings, in which

Fig. 1 shows the cross section of a two-shaft turbo fan motor with manifold and nozzles for washing according to the prior art.

Fig. 2 shows the manifold installed at the entrance of an air motor in accordance with the prior art.

Fig. 3 shows a washing unit with a contactless spray head that is outside the scope of the invention.

Fig. 4a shows the application of the washing unit of fig. 3 when washing a motor mounted "under the wing".

Fig. 4b shows the application of the washing unit of fig. 3 when washing a motor mounted "in the tail".

Fig. 5 shows details of the spray head of the washing unit of fig. 3.

Fig. 6 shows an alternative example of the spray head.

Fig. 7a shows the washing of the fan of a turbo fan motor using the washing unit of fig. 3.

Fig. 7b shows the washing of the central motor of a turbo fan motor using the washing unit of fig. 3.

Fig. 8 shows how the washing procedure is controlled by means of a chamber and a distance measuring device installed in the spray head.

Fig. 9 shows a universal spray head according to the invention.

Fig. 10 shows the universal spray head and a wastewater collection device with wastewater treatment for reuse of the washing liquid.

Description of the preferred embodiment

The manifold described here is universal in the sense that it can serve small engines as well as large engines since the manifold has capacities for multiple sizes. A manifold that has capacities for multiple sizes eliminates the difficulty of manufacturing many manifolds for aircraft engines of varying sizes.

Fig. 3 shows the application of a universal manifold that is outside the scope of the claims. An air motor 1 installed in an airplane (not shown) is subjected to washing. The washing unit 31 is a unit for delivering washing liquid to a spray head 33. The spray head 33 includes a manifold 36 to distribute the liquid to the nozzles (not shown for clarity) on the manifold 36. The nozzles inject the washing liquid at the motor inlet. The nozzles can either spray the liquid or inject the liquid as a solid stream. The washing unit 31 comprises the necessary equipment and components to allow the washing of items such as tanks for storing washing liquid, heaters for heating the liquid, a pump for increasing the pressure of the liquid, controls required to allow and monitor the operation washing The liquid may be water only or water with chemical substances or chemical substances only such as solvents. Typically the liquid is heated since washing with hot liquid improves the washing result. The washing liquid is pressurized by the pump for distribution to the nozzles. The controls typically comprise a liquid manometer, a liquid flow meter, a liquid temperature meter and a pump on / off switch. The washing unit 31 can then be mobile so that it is practical for the use of washing aircraft engines at an airport. The washing unit 31 may then be part of a vehicle 32. The vehicle 32 may be a hand-drawn truck or a motorized truck or a vehicle carried by a person such as a small truck. Alternatively, the washing unit 31 may not be mobile.

The spray head 33 is held in a fixed position at the inlet of the motor 1 by the robotic arm 34. The robotic arm 34 is at one end installed on the washing unit 31 and has a spray head 33 at the other end. The robotic arm 34 has at least one articulated joint and a stump that allows proper positioning of the spray head 33 at the inlet 301 of the engine 1. The robotic arm is mobile with at least three degrees of freedom. The robotic arm 34 operates by means of a hydraulic operating device

or pneumatic or electric or mechanically hand-held (not shown) or can be moved by hand. In one embodiment of the present invention, the robotic arm may comprise one or more telescopic parts. For example, a part between two joints can be telescopic.

The spray head 33 is sized to be smaller than the inlet opening 301. The spray head 33 is preferably positioned at the inlet 301 by the operating robotic arm 34 from a control panel (not shown) by an operator. The spray head 33 is essentially positioned in the center of the inlet opening 301. When the spray head 33 is in its proper position there is no contact between the plane and the spray head or any other parts of the washing device. The washing unit 31 delivers the pressurized washing liquid to the spray head 33 through the conduit 35 where the conduit 35 comprises either a flexible hose or a similar device for that service. In the spray head 33 the liquid is distributed to a manifold of nozzles by means of manifold 36 where the nozzles are intended to inject the washing liquid into the engine.

Figure 4a exemplifies the washing unit 31 when it is in position for use when washing an engine of an 'engine under the wing' type aircraft. Similar parts have been shown with the same reference numbers as in fig. 1 and in fig. 3. The plane 40 has a wing 41 on which the engine 1 is installed. The vehicle 32 with the washing unit is parked next to the engine. The vehicle 32 is preferably parked on one side of the engine so that it does not remain in the direct air stream during washing. This is to prevent any loose objects in the vehicle from being accidentally carried by the air flow to the engine. The robotic arm 34 keeps the spray head with its manifold 36 in position at the motor inlet. There is no contact between the plane and the manifold or any other parts of the washing unit. Fig. 4b exemplifies the washing unit 31 when it is in the use position when washing an engine of an "tail engine" type airplane. Similar parts are shown with the same reference numbers as in fig. 1 and in fig.

3. The vehicle 32 with the washing unit is parked next to the engine. The robotic arm 34 keeps the spray head and its manifold 36 in position at the motor inlet. There is no contact between the plane and the manifold or any other parts of the washing unit. The washing unit is not limited to the illustrations in fig. 4a and in fig. 4b since there are many other planes of different designs in which the washing unit (31) is equally applicable. There may also be airplanes in which it is beneficial to provide that the washing equipment be supported by the fairing or other parts of the aircraft.

Fig. 5 shows the details of the spray head 33. The spray head 33 is shown in a perspective view where the arrow shows the direction of engine air flow. Similar parts are shown with the same reference numbers as in fig. 3. The spray head 33 comprises a unit with essentially rotational symmetry, the axis 501 being the center of symmetry. When the spray head 33 is in the position for washing, the shaft 501 is essentially aligned with the center of symmetry of the motor shaft. The spray head 33 has a central body 509. The body 50 has a front end 58 facing the engine. The body 50 has a rear end 59 opposite the front end 58. The rear end 59 is connected to the robotic arm 34. The body 50 includes an optical detector device 55 used as an aid to position the spray head 33 and to monitor the operation. washing The optical detector device 55 is essentially directed towards the motor inlet. The optical detector device 55 may comprise a camera in which the camera vision can be instantly seen by the operator on the control panel. Alternatively, the optical detector device may comprise a fiber optic device for the same purpose as the camera. Alternatively, there are other means of recording the sight of the spray head. The optical detector device 55 serves the purpose of delivering a view of the motor input to the operator. The camera view is used to help the operator align the spray head with the center of the engine shaft by maneuvering the robotic arm from the operator control panel. In addition, the camera view allows the operator to position the spray head at the appropriate distance upstream of the engine. In addition, the camera's vision allows the operator to monitor the washing process by delivering a view from the center line of the engine during washing. In addition, the camera view helps the operator to make the decision in adjusting any wash parameter from the view that the camera delivers. In addition, the camera's vision is a device that improves safety since the operator can stop the washing process when he observes something in the camera.

The body 50 in fig. 5 includes a distance measuring device to measure the distance to the engine. Typically the distance measuring device comprises a transmitter 56 and a receiver 57. The distance measuring device could comprise a sound detecting device such as an ultrasonic detecting device where the transmitter emits a sound beam that is reflected on the conical part of the nose of the engine and where the

reflected beam is received by the receiver. The distance from the transmitter to the receiver is then estimated by the time difference for the signal from the transmitter to the receiver. Alternatively, the distance measuring device could be an optical measuring device such as a laser in which the transmitter emits a laser beam that is reflected on the conical part of the nose of the motor and is received by the receiver. Alternatively, there are other distance measuring devices that could be used. The recorded distance is delivered to the operating panel where the operator will use the information when adjusting the proper position of the spray head upstream of the engine. During washing the measured distance helps the operator to control the washing process by reporting any changes in the distances. The distance measurement helps the operator make the decision to adjust any washing parameter if he finds that the distance is not appropriate. The distance measuring device is a safety improvement device since the operator can stop the washing process if he finds that the distance is not safe. The distance measuring device may include alarms that emit an alarm signal in the form of an acoustic sound or a slight flash if the distance is out of range. For example, if the measured distance decreases below a predetermined value. This limit value can be adjusted by the operator through the control panel.

The body 50 includes a lamp 52 to illuminate the motor inlet. The lighting improves the vision from the camera as well as the direct contact vision of the eye with the motor inlet. The body 50 may include another device to improve safety or to improve the washing operation.

As one skilled in the art readily perceives, each of the following characteristics can be achieved: the optical sensing device 55, the distance measuring device 56, 57, or the lamp 52 can be used independently of the others. That is, the spray head 33 may, for example, include only the optical detecting means 55 or only the distance measuring device 56, 57.

The spray head 33 in fig. 5 shows the manifold as an annular tube, that is, a toroid. The liquid is pumped from the washing unit (not shown) through a hose (not shown) to the manifold

36. The manifold 36 is essentially circular with the center of the circle aligned with the axis 501. The plane of the manifold 36 is essentially perpendicular to the axis 501. The manifold 36 is connected to the body 50. The manifold 36 has multiple nozzles arranged around the manifold for different washing services. For example, the nozzle 53 serves the purpose of washing the motor fan. The nozzle 54 serves the purpose of washing the motor core. The nozzle 510 serves the purpose of washing the conical part of the nose. The nozzle 511 serves the purpose of washing the fairing. In addition to the nozzles 53, 54, 510 and 511 the manifold may comprise other nozzles (not shown) for washing other engine details. The manifold 36 has at least one nozzle 54. The nozzles can spray the liquid in a droplet spray. Alternatively, the nozzles can deliver the liquid as an unsprayed jet. The objective of using annular manifolds is that the manifolds can be manufactured from a tube that is curved to a ring requiring only a joint (a weld). This is an advantage over alternative designs that require more joints. Any reduction in the joints is considered as a safety feature since the joints can break and can cause damage if the loose parts enter the engine. In addition, the ring-shaped manifold is considered safe since any accidental contact between the manifold and any parts of the aircraft would not imply contact with any sharp edge. Alternatively, the manifold can be equipped with a cushion such as rubber sponge material (not shown) so that it absorbs any force in case of accidental contact with the engine.

Fig. 6 shows an alternative spray head. Similar parts are shown with the same reference numbers as in fig. 3 and in fig. 5. The ring-shaped manifold is here replaced by tubes 61 that hold the nozzles in position. Alternatively, the manifold can be made differently.

Figs. 7a, 7b and 8 show the application of the washing unit (31) when a turbo fan motor is washed. Similar parts are shown with the same reference numbers as in the previous figures. Fig. 7a shows the fan wash of the turbo fan motor 1 by using nozzles to wash the fan. During washing the fan is forced to rotate through the use of the engine starter. The nozzle 53 is atomizing the spray wash liquid 71. The nozzles have a spray design that results in a limited liquid distribution on one side by the current line 75 and on the other side by the current line 76 The distribution of the spray on the leading edge of the fan blade 72 is essentially equal to the entire length of the blade limited by point 702 of the tip and point 701 of the hub. The spray thus covers the entire length of the blade. The manifold 51 may comprise only one nozzle 53 which then covers only a part of the engine inlet. The humidification of the complete fan is then achieved by the rotation of the fan. Fig. 7b shows the washing of the engine core of the turbo fan motor 1. During washing the motor shaft is rotated by using the starter motor. The nozzle 54 is atomizing the spray wash liquid 73. The nozzles have a spray design that results in a limited liquid distribution on one side by the stream line 77 and on the other side by the stream line 78 The purpose of the spray is to deliver liquid to the inlet 74 of the motor core. The inlet of the motor core is limited by the air splitter 705 and a point 704 on the

hub on the opposite side of the air splitter 705. The spray distribution at the engine core inlet is equal to the opening of the engine core inlet limited by the air splitter 705 and point 704. Thus the liquid emanating from the nozzle 54 will enter the inlet 74 of the motor core. In addition, the nozzle 54 is oriented so as to allow the liquid to penetrate between the blades during fan rotation. Fig. 7a and fig. 7b describe the washing of the turbo fan motor by using the engine starter. Alternatively, another starting device such as a separate APU starter can be used. Alternatively, washing can be conducted without rotating the motor shaft.

Fig. 8 shows the use of the camera and the distance measuring device. Similar parts are shown with the same reference numbers as in the previous figures. A chamber 55 has a viewing angle limited by lines 81. The chamber will provide a view of the conical part of the nose of the engine that allows the operator to move the spray head to the proper position for washing. When the engine is driven by its starter, the camera's vision is used to monitor the rotation of the tree. The camera can then be attached to a computer device (not shown) with software to estimate rotational speed. The rotational speed serves as an input parameter to the operator when starting the pumping of the liquid. Having rotational speed control is essential for a good wash result. In addition, the vision of the camera allows to see the distribution of the liquid on the fan as well as the penetration of the liquid in the motor core.

This vision serves with an important input to the operator since it can adjust the positioning of the spray head or adjust the washing parameters so that they better serve their objectives. To prevent the camera lens from becoming contaminated with aerial liquid, the lens is purged by a stream of air supplied from a source of compressed air (not shown). The distance measuring device comprises a transmitter 56 that emits a beam 82 towards the conical part 83 of the nose where the reflected beam is reflected and returned to the receiver 57. The signal is fed to a computer unit (not shown) to calculate the distance . The computer unit can be set up with alarm levels so that it provides, for example, an acoustic alarm, if the distance to any object is critically short. The distance measuring device can be directed towards objects other than the conical part of the nose at the motor inlet so as to provide information on measured distances. To prevent the sensors of the measuring device from being contaminated with airborne liquid, they are purged by a stream of air supplied from a source of compressed air (not shown).

Fig. 9 shows a universal spray head according to the invention and which will serve a wide range of engines of different sizes. Spray head 90 is shown in a perspective view where the arrow shows the direction of air flow. Spray head 90 has a central body 91 with camera, distance measuring device and lamp similar to that described above in spray head 33 in fig. 5. The spray head 90 comprises several manifolds 92 annularly each with a different diameter. The rings 92 are arranged symmetrically around the central axis 501. The rings 92 are all essentially in the same plane where the planes are essentially perpendicular to the axis

501. The rings are arranged with a gap between rings so that they allow air to flow through the spray head. Each ring comprises one or multiple nozzles 93 where the type of nozzle, the number of nozzles and the separation between nozzles is consistent with the washing service that the ring will do. The nozzles can be used to wash the fan, the motor core, the fairing, the conical part of the nose or for a similar service. In principle, inner rings are used to wash smaller engines while outer rings are used to wash larger engines. In addition, a ring may be dedicated to washing a specific type of engine or a specific family of engines. The ring with the largest diameter, that is to say the outer ring, has a diameter smaller than the diameter of the entrance fairing of the smaller engines that will be serviced by the spray head. For example, the engines of popular commercial airlines that carry passengers have a variable fairing diameter of between 1.5 and 3 m. The spray head to service these engines would then have an outside diameter of less than 1.5 m.

To wash an engine typically only one ring is in service. This is achieved by having each ring 92 connected through a conduit to a distributor (not shown for clarity) in the spray head. The distributor comprises individual valves to close each duct. Before establishing the wash, the operator would activate the ring to be used by opening the corresponding valve. All other valves would then be closed.

Although spray head 90 is universal in the sense that it can service a wide range of aircraft types and engine types, it is practical to have multiple spray heads that are interchangeable. This can be reasoned by different requirements established by aviation institutions or other instructions. Another reason may be a separate spray head to meet military aviation requirements. There may be additional reasons. In order to change the spray heads, the spray head is mounted on the robotic arm with a coupling that allows easy exchange.

The invention as described herein provides means to reduce washing time as well as to reduce work requirements. Fig. 10 shows the willingness to wash engines that requires both less time and less labor intensity compared to the prior art. Similar parts are shown with the same reference numbers as in the previous figures. The process described here would typically require only one operator 5 to conduct the wash. A washing unit 31 supplies washing liquid through the conduit 35 to a spray head held by the robotic arm 34. During washing the operator controls the process from the control panel 113. Control includes viewing the image of the chamber of the spray head from the monitor

112. The residual washing liquid that emanates from the engine is collected by the collection device 114 at the rear of the engine. The collected residual liquid enters a tank (not shown) in the unit 116 through the conduit 115. The unit 116 may be equipped with wheels for mobility. A suitable collection device is described in the international application PCT / SE 2004/000922, in which the content of said application is included herein by reference. The residual liquid is pumped through the conduit 118 to a reservoir in the washing unit 31 where the unwanted accumulation material released is separated from the liquid by an appropriate wastewater treatment process. The treated water will then be used to wash the

15 next engine or it will be discharged to a sump. While the wastewater is being treated the operator can move his vehicle 32 and other equipment to the next engine to adjust it for the next wash.

Although a specific embodiment has been shown and described herein for purposes of illustration and exemplification, it will be understood by those skilled in the art that the specific embodiment shown and described can be substituted for a wide variety of alternative and / or equivalent implementations without leaving of the framework of the present invention. Consequently the present invention is defined by the texts of the appended claims.

Claims (14)

1. A washing system for washing a gas turbine engine (1) of an airplane (40) comprising: a spraying device (90); a washing unit (31,35) adapted to distribute washing liquid to said spraying device (90); Y a positioning device (34) adapted to place said spraying device (90) thereby allowing a positioning of said communication device (90) in a washing operation position relative to an inlet (110) of said motor (1 ) gas turbine, characterized in that the spraying device (90) includes: a central body (91); several manifolds (92) annularly each with different diameters, arranged symmetrically around the central body (91); Y multiple nozzles (93) arranged symmetrically around the central body (91), the nozzles (93) being arranged around the manifolds (92) and adapted to inject said washing liquid into said inlet (110) of the engine during a washing operation , wherein said spraying device (90) comprises a unit with essentially rotational symmetry with an axis of symmetry (501) being the center of symmetry; Y wherein, when the spraying device (90) is in said washing operation position, the central axis (501) of the spraying device (90) is essentially aligned with the motor shaft of the turbine engine (1) of gas. 2. The washing system according to claim 1, wherein said positioning device (34) comprises a robotic arm (34) that includes joints that allow movement of said spraying device (90) in said three dimensions. 3. The washing system according to claim 2, wherein said robotic arm (34) includes at least one telescopic part. 4. The washing system according to claim 1, 2 or 3, further comprising a control panel (113) adapted to allow an operator to adjust the position of said spraying device (90) in three dimensions relative to said motor input (110) by means of said positioning device (34). 5. The washing system according to claim 4, wherein said spraying device (90) further comprises an optical detector device (55) adapted to monitor a washing operation of a motor (1). 6. The washing system according to claim 5, wherein said optical detector device (55) is connected to said control panel (113) and is adapted to deliver a view of said motor inlet (110) to an operator of said washing system on a monitor (112). 7. The washing system according to claim 5 or 6, wherein said optical detector device (55) comprises a chamber. 8. The washing system according to claim 5 or 6, wherein said optical detector device (55) comprises a fiber optic device. 9. The washing system according to any of the preceding claims 5-7, wherein said spraying device (90) further comprises a distance measuring device (56, 57) adapted to measure the distance between said spraying device ( 90) and said motor (1). 10. The washing system according to claim 9, wherein said distance measuring device (56, 57) is connected to said control panel (113) and is adapted to deliver an indication of the distance between said communication device (90) and said motor (1), thereby informing an operator of a current distance between said spraying device (90) and said motor (1) by means of said monitor (112). 11. The washing system according to claim 9 or 10, wherein said distance measuring device (56, 57) is an ultrasonic detector device comprising a transmitter (56) adapted to emit a sound beam and a receiver (57) adapted to receive said beam, in which said distance is estimated by the time difference for said beam from said transmitter (56) to said receiver (57). 12. The washing system according to claim 9 or 10, wherein said distance measuring device (56, 57) is an optical measuring device comprising a transmitter (56) adapted to emit a laser beam and a receiver (5). 57) adapted to receive said beam, in which said distance is estimated by the time difference for said beam from said transmitter (56) to said receiver (57). 13. The washing system according to any of the preceding claims 8-12, wherein said distance measuring device (56, 57) further comprises an alarm means adapted to emit an alarm signal if said measured distance decreases below of a default value. The washing system according to any of the preceding claims, wherein said spraying device (90) further comprises lighting means (52). 15. The washing system according to any of the preceding claims 1-13, wherein said spraying device (33) comprises at least one tube (61) disposed in a body (50), at least said duct ( 61) with at least one nozzle (54).